Positive drive, endless rubber tracks such as those used on agricultural or industrial vehicles typically have an internal, center row of individual drive lugs which engage drive bars on a drive wheel. The continued use and contact between the drive bar and drive lugs cause internal lug stresses and surface wear at the points of contact. Additionally, the internal, center row of lugs are typically functioning not only to transmit power from the drive wheel to the track, but also to retain the track on the vehicle. Contact between the vehicle undercarriage wheels and lateral end of the guide surfaces of the inner lugs frequently occurs as the vehicle maneuvers during normal service. This contact can cause wearing of the inner lugs, which can be severe, depending upon various vehicle design features and application use. Driving and/or guiding forces on the inner lugs, henceforth referred to as guide-drive lugs, can lead to cracks and eventual chunking of the rubber surface, and possibly to complete removal of the drive lugs, making the track unserviceable. Thus, a track belt having guide-drive lugs which are stronger and more resistant to wear is desired.
United States Patent Publication No. 2008/0136255 A1 discloses an endless track belt for use in an industrial or agricultural vehicle. The endless rubber track belts described therein include a rubber carcass having an inner surface having one or more drive lugs and an outer surface having tread lugs. The drive lugs include reinforcement layers that partially or substantially cover all or a portion of the end faces of the drive lugs. The reinforcement layers may include continuous strips, or discrete strips. The reinforcement layer may also be fabric cutouts to match the shape of the drive end faces of the drive lugs.
U.S. Pat. No. 6,974,196 B2 describes an endless track for an industrial or agricultural vehicle consisting of a body formed of a rubber material having an outer surface displaying a series of ground engaging profiles longitudinally spaced along the surface and an inner surface displaying a series of longitudinally spaced drive lugs adapted to be engaged by drive sprockets on the vehicle driving assembly. The body of the endless track is fabric reinforced. One layer of fabric longitudinally extends at a distance from the inner surface of the track and has a width slightly less than the width of the drive lugs so that the fabric may extend inside the drive lugs to increase their rigidity.